1. Field of the Invention
The present invention relates generally to the field of computer-implemented inventions, and more specifically, to a computer-implemented system and method for designing a pressure-dosed drain field.
2. Description of the Related Art
Pressure-dosed drain fields are typically used for wastewater treatment in connection with homes, clustered communities and commercial developments that are not connected to municipal wastewater treatment plants and for which a gravity drain field is not suitable. A pressure-dosed drain field is one in which the wastewater is discharged through a network of pipes over a certain area. The discharge or “dose” is released through orifices in the piping at timed intervals or according to wastewater production. Regulations typically specify a certain minimum pressure requirement for the most distant (or “distal”) orifice in the system and require that the pressure in all of the other orifices in the system may not deviate from the pressure in the distal orifice by more than ten percent (10%). The regulations also typically establish the minimum volume of wastewater that must be delivered into the piping system per dose.
There are several factors that go into designing a pressure-dosed drain field system, including, but not limited to: the type of pump used (the pump is located in the pump chamber, which is located at the septic tank); the length and diameter of the forcemain (which is the pipe that leads from the pump chamber to the drain field); the length and diameter of manifold segments (which connect to the laterals); the number, spacing, length, diameter and elevation of the laterals; and the number, spacing and diameter of the orifices on the laterals. Currently, these calculations are done on spreadsheets and are based on little more than educated guesswork. In fact, it is not uncommon for drain fields to be out of compliance with regulations that require the deviation in pressure of the fluid emanating from the orifices not to deviate by more than 10% of the pressure in the distal orifice. Thus, there is a need for an automated system that would allow engineers to design pressure-dosed drain fields with confidence that the regulatory requirement of relatively even pressure throughout the pressure-dosed drain field system will be met.
The prior art includes computer systems for dealing with various aspects of wastewater treatment systems, but none of these systems provides a mechanism for designing a pressure-dosed drain field. The two patents discussed below deal with wastewater collection, whereas the present invention deals with draining wastewater after it is collected. Out of the three patent applications discussed below, the only one that deals with wastewater dispersal is Zupancic, but Zupancic deals with an entirely different type of wastewater treatment system than the present invention.
U.S. Pat. No. 5,063,505 (Pate et al., 1991) deals with a sewer system where wastewater is collected from homes and buildings and pumped to a treatment plant. A database ascertains the wastewater flow and surface hydraulic grade so that the operators of the plant can determine whether their systems are working. In short, the Pate invention is a system for managing a public wastewater collection system. This invention has nothing to do with pressure-dosed drain fields or designing a wastewater treatment system.
U.S. Pat. No. 6,556,924 (Kariyawasam et al., 2003) describes a computer-implemented system for determining optimal repair options for cast iron and ductile iron water or wastewater pipe sections. The focus of this system is on maintenance, not design. Furthermore, iron pipes generally are not used in pressure-dosed drain fields; therefore, this patent is not relevant to the present invention.
U.S. Patent Application Pub. No. 2007/0012609 (Zupancie et al.) involves subsurface drip irrigation dispersal of sodic water generated as a result of drilling for coal bed methane. The present invention does not involve a drip irrigation system, and the Zupancic system does not involve the same relatively high pressure levels associated with a pressure-dosed drain field. In fact, the Zupancic system has nothing to do with the problem that the present invention solves, namely, the design of a pressure-dosed drain field that provides relatively uniform pressure rates at all of the orifices throughout the system. The problem of maintaining relatively constant pressure throughout the system simply does not exist with the Zupancic drip dispersal system because the drip emitters control the pressure.
U.S. Patent Application Pub. No. 2003/0236639 (Curry) describes a method of analyzing sewer flow in an open channel that is carrying untreated water to a treatment plant. In a pressure-dosed drain field, the pipes are fully pressurized during a dose; therefore, the Curry method is not relevant to the present invention and deals with an entirely different problem.
U.S. Patent Application Pub. No. 2005/0258106 (Cape, Sr.) discloses software that controls the movement of a batch of wastewater through a wastewater treatment device. The present invention, on the other hand, relates to the draining of wastewater after it has been treated; therefore, the Cape invention is not relevant to the present invention.
As is apparent from the above discussion, there is no prior art that deals with the problem of designing a pressure-dosed drain field that will meet regulatory pressure requirements to a very high level of accuracy. Accordingly, there is a need for a system and method that allows engineers to design wastewater treatment systems—and more specifically, pressure-dosed drain flelds—for homes, clustered communities and commercial developments that are not connected to municipal wastewater treatment plants and that, for a variety of reasons, cannot be served by standard septic tank/gravity-dosed drain field combinations. Ideally, the system would provide engineers with confidence that the systems they design will be in compliance with regulatory requirements for the minimum pressure at the distal orifice and the establishment of relatively constant pressure throughout all of the orifices in the system.